How does 2-payment-per-quarter limit work for estimated tax payments?

[seanbook]

The IRS website says the limit of estimated tax payments is two payments per quarter. I'm wondering anyone knows how exactly this quarterly limit work. In my case, I made two Q1 payments in March. Can I make my Q2 payments in May or I have to wait for 90 days from my last payments?

[fanfare]

your 2nd quarter ES installment due by 6/15 you should be able to pay now.

I don't know about any restriction to topping up your second ES payment with more by 6/15.

Where is that stated on the IRS website?

@seanbook 

[seanbook]

Here's the frequency limit. Look for the row for Estimated Tax.

Frequency Limit Table by Type of Tax Payment | Internal Revenue Service (irs.gov)

PS: Intuit kept modifying the link for some reason. Just web search for "Frequency Limit Table by Type of Tax Payment" and you'll find the IRS page.

[fanfare]

the first interval (quarter) has ended and we're in the second interval now.

you don't have to wait 90 days.

@seanbook